Straightening machine



June 25, 1968 w. 1.. SIEGERIST ET AL 3,389,589

STRAIGHTENING MACHINE 8 mm 5 S .8

INl/ENTORS g y HTTQRNEKS Filed May 16, J.

5 mm mm M a @K w o$ mm mm. l m mm 5 K mm (INN MN K 3 Sheets-Sheet 2 Filed May 16, 1966 United States Patent 3,389,589 STRAIGI-ITENING MACHINE Walter L. Siegerist and Harvard K. Hecker, St. Louis, Mo., assignors to The Medart Engineering 8: Equipment Company, St. Louis, Mo., a corporation of Missouri Filed May 16, 1966, Ser. No. 550,221 6 Claims. (Cl. 72-164) -This invention relates to an improved straightening machine of the kind through which tubes, rods, shafts, and the like, are fed for straightening, sizing, and polishing. Like some other straightening machines, this machine has two rolls, one being a concave roll and the other being a straight roll, and the tubes, rods, and shafts are fed between these two rolls. The rolls are movable relative to one another, and they are each rotatable to adjust the angle between their axes. These motions are necessary in any straightening machine. Heretofore, mechanical means were used to apply pressure to the rollers. However, as better materials and stronger alloys for tubes, rods, shafts and the like have been developed, these me chanical means have grown quite cumbersome and have actually impeded the eflicient operation of present conventional machines by preventing rapid positioning of the rollers.

Hydraulic pressure is used to hold the rolls in the desired relatively spaced positions against the forces of the tubes, rods, and shafts fed between the rolls which tend to separate the rolls. In conventional straightening machines, as many as six hydraulic cylinders have been used to supply the necessary pressure.

High force of the foregoing kind is required not only because of the force tending to separate the rolls as the bars are fed between them, but also because of the relative angle between the axes of the rolls. As bars are fed between the rolls, the one which is movable toward and away from the other one also tends to rotate to relieve the pressure of the straightening effect of the rolls on the rod being fed between the rolls. To do the straightening job, the selected angle between the axes of the rolls must be maintained with greater force; yet the angle must be instantly adjustable. In fact, high roll angles are desirable in modern bar mill practice to increase the production of straightening bars and rods to commercial tolerances. The hydraulic force in the mechanism for moving one of the rolls must be sufficiently great to prevent relative movement of the rolls against the forces tending to separate them while still allowing instant adjustment of the amount of bend exerted on the bars being fed through the machine.

The general object of this invention is to provide a straightening machine having the foregoing characteristics. A particular object of the invention is to provide a straightening machine having a high capacity hydraulic apparatus for moving one of the rolls rapidly relative to the other and for holding the position of that roll against forces tending to change the angular position.

Another object of the invention is to provide a straightening machine that has a unique high capacity cylindrical ram for moving one of the rolls toward the other one, with a small capacity hydraulic cylinder for rapidly moving that roll to or from the other one, much less force being required for the smaller cylinder, and with positive locking elements engageable to prevent withdrawal by the small cylinder until pressure of the cylindrical ram is relieved.

Another object of the invention is to provide a straightening machine for supporting one of the rolls, wherein there is no relative motion between the roll, roll carrier and cylindrical crosshead, but the entire roll carrier and cylindrical crosshead can .be instantly rotated to vary the rolls axial angle.

3,389,589 Patented June 25, 1968 A particular object of the invention is directed to fast acting and strong apparatus for adjusting the relative positions of the rolls under full hydraulic pressure between which the tubes, rods, and shafts are fed, and for rigidly holding those adjusted positions against the great counter forces produced by the straightening, sizing, or polishing operation.

Still another object of the invention is to provide a straightening machine having a large cylindrical hydraulic ram for moving one of the rolls toward the other one rapidly, and with a high holding force; and an object is to provide means for repeatedly returning the rolls to the original position to facilitate the feeding of crooked bars when open and yet provide accuracy of positioning when closed by means of hydraulic forces in excess of those actually required for straightening for the highest precision straightening, heretofore afforded only by fixed crosshead types of straightening.

Still another object of the invention is to provide a means for rapidly conveying a bar that has just been inspected to the output side of the machine without further straightening, sizing and polishing. When the hydraulic force of the ram is released and the motor reversed, the bar separates the rolls automatically and only enough force is applied to rotate the bar and cause it to return to the input side.

A specific object of the invention is to provide a straightening machine having a large cylindrical crosshead to which a roll is fastened and which is rotatable to vary the angular position of the roll, the crosshead eliminating the need for hydraulic or manual roll locks usually required to maintain a set angular position of the axis of the straight roll.

A further object of the invention is to provide a straightening machine having the foregoing characteristics, and also being capable of quick adjustment of the spacing between the concave and straight rolls, and having quick opening means to quickly separate the rolls for the passage of enlarged ends of bars, rods, or tubes.

Another object of this invention is to provide a means for positively positioning the hydraulic ram against a fixed stop with a given hydraulic pressure while providing means to back the ram away from that position by means of variable hydraulic pressure, thereby providing a safety device against the inadvertent feeding of oversized bars through the machine.

Other objects and advantages will be apparent to those skilled in the art.

In the drawings:

FIGURE 1 is a schematic side elevation view of the straightening machine;

FIGURE 2 is an end elevation view of the straightening machine;

FIGURE 3 is a fragmentary top plan view of the concave and straight rollers as removed from the machine, but showing portions of the supporting frame for the straight roller and showing the crosshead, gear train and related frame generally in longitudinalrnedial section. The rollers as shown in FIGURE 3 are not in their normal operating positions at which their axes would be at an angle to one another.

FIGURE 4 is a fragmentary enlarged 'section view showing the gear arrangement at the upper portion of the frame and crosshead;

FIGURE 5 is an enlarged fragmentary view in section showing the gear arrangement at the lower portion of the crosshead;

FIGURE 6 is an enlarged fragmentary view in section taken generally along the line 6-6 of FIGURE 3;

FIGURE 7 is a view in section taken substantially along the line 7-7 of FIGURE 3;

FIGURE 8 is a view in section taken substantially along the line 88 of FIGURE 3;

FIGURE 9 is an end elevation view on a reduced scale showing the end of the crosshead to which the roller supporting plate is adapted to be mounted; and

FIGURE 10 is a longitudinal sectional view of said crosshead.

Referring now to the drawings, FIGURE 1 and 2 show a typical straightening machine with which this invention may be used. In the straightening machine shown in FIGURES l and 2, there are the essential parts, including a main frame 21 which is stationary and mounted on any shop floor. On one side 22 of the frame, a concave roller assembly 23 is supported. On the other side 24 of the frame, a straight roller assembly 25 is supported. An adjusting shaft 26 is provided to permit adjustment of the angle of the concave roller 23 by adjusting the position of its axis, as is conventional. A similar shaft 27 permits adjustment of the angle of the straight roller assembly 26 by adjustment of the angle of the axis of the straight roller.

Referring now to FIGURE 3, a frame section 30 is shown fastened by bolts 31 through a plate 22a to the side 22 of the frame 21, the plate 22a being a means which permits rotation of the frame section 30 in a manner known in the art. A pair of large bearings 32 and 33 are supported on the frame section 30. A concave roller 34 is journaled between the bearings 32 and 33 on a shaft 35 to which a universal joint 36 is mounted and connected through a series of similar universal joints and bearings to a drive motor (not shown).

The straight roller assembly 25 comprises a frame part 40 fastened by bolts 41 to the side 24 of the main frame 21, therefore being stationary with the main frame. The frame part 40 has a bore 42 through it with an inwardly extending annular lip 43. Adjacent the side 24, the bore is enlarged to provide an annular recess 44 bounded on one side by an annular shoulder 45 and on the other side by a metal ring 46 fastened to the side 24 of the main frame 21.

The side 24 also has a bore 48 through it coaxial with the bore 42. A bronze bearing wall 49 lines the bore 48. The bearing wall 49 may have an overlying radially out- Wardly extending flange 50 which may be fastened with the annular ring 46 to the side 24 by common pins 51.

A ring gear 54 is mounted in the annular space 44 between the wall 45 and the annular ring 46. The ring gear 54 has external teeth 55 which extend generally parallel to its axis, and has internal circumferential threads 56. A worm 58 is fixed to a shaft 59 supported by the stationary main frame 21. The teeth 60 of the worm 58 are in mesh with the external teeth 55 of the ring gear 54.

The shaft 59 is journaled in bearings 62. A spoked hand wheel 64 is fastened to the end of the shaft 59 to rotate the shaft and the worm 58, thereby to slowly rotate the ring gear 54 for a purpose to be described.

There is a frame section 68 extending within the bore 42 and the annular lip 43. The frame section 68 is generally cylindrical, with external circumferential threads 69 in mesh with the internal threads 56 of the ring gear 54. The frame section 68 also has a cylindrical inner wall 70 with a bronze sleeve cylinder 71. A plate 72 is welded to one end of the frame section 68.

The frame section 68 is moved axially when the ring gear 54 is rotated by the worm 58.

A cylindrical hub 75 extends from the end wall 72 in coaxial relationship with the cylindrical frame section 68. The side wall of the hub 75 has a cylindrical outer surface 76, and the hub has a recess defined by a generally cylindrical inner surface 77. There is also an end wall 78 having a piston face 79 on one side and a central boss 80 extending from the other side 81. There are reinforcing side ribs 82 extending from the inner surface 77 to the central boss 80. Also, there is a fluid passage 83 extending through the hub 75 and opening through the end wall 78 and the face 79.

Diametrically opposing one another, there are lugs 84 and 85 extending outwardly from the outer surface 76 of the hub 75. The lugs 84 and 85 each extend approximately one-fourth of the distance around the circumference of the hub 75.

A crosshead has a cylindrical wall 91 positioned between the frame section 68 and the hub 75. The wall 91 has a cylindrical outer surface 92 in contact with the stainless steel sleeve 71. The wall 91 also has a cylindrical inner wall 93 extending inwardly from the inner end 94 of the wall 91. There are a pair of inwardly extending lugs 96 and 97 with spaces 98 and 99 between them which are as wide or wider in a circumferential direction as the width of the lugs 84 and 85 on the hub 75. The lugs 96 and 97 have faces 100 and 101 which act as stops against which the lugs 84 and 85 make contact as will be described. The lugs 84 and 85 and the lugs 96 and 97 provide a kind of bayonet joint permitting assembly of the crosshead 90 with the frame and thereafter providing stops to limit axial movement of the crosshead.

There is another cylindrical wall section 103 beyond the lugs 96 and 97 leading to an annular shoulder 104. Another inner cylindrical wall 106 leads from the shoulder 104 to a wall 107 having a face 108 opposing the face 79 on the hub 75. The wall 106 is in sliding contact with the outer cylindrical wall 76 on the hub 75.

A plate 110 is fastened by a plurality of bolts 111 to the end 94 of the wall 91. As FIGURE 8 shows, the plate 110 has two openings 112 and 113 through it. An extension 114 surrounding the fluid passage 83 extends from the hub 75 and is welded to the plate 72. Another extension 115 extends from the hub 75 and is also welded to the plate 72. The extension 115 is complementary in shape to the shape of the opening 113, as shown in FIG- URE 8. As FIGURE 5 shows, there is a hole 116 through the plate 72 to permit passage of a hose or pipe 117 threaded to the fluid passage 83.

There is a conventional annular packing 120 between spaced conventional retainers 121. The annular packing 120 lies between the inner wall 93 of the crosshead and the outer cylindrical wall 76 of the hub 75.

Beyond the wall 91, the crosshead 90 has an enlarged head 122 with an outer cylindrical wall 123 that slides within the stainless steel bearing wall 49. A plate 124 is fastened by a plurality of bolts 125 to the head 122. A pair of bearings 126 and 127 are fastened by bolts 128 to the plate 124. A straight roll 129 is journaled between the bearings 126 and 127 on a shaft 130. A Wobbler portion 131 on a universal joint is connected to the end of the shaft and is connected through universal joint connections to be driven by a motor (not shown) to rotate the straight roller 129.

A small piston and cylinder assembly 136 is provided to back the straight roller 129 away from the concave roller 34. This piston and cylinder assembly 136 comprises a cylinder 137 with a piston 138 slidable therein. A rod 139 is connected to the piston and leads through the end of the cylinder 137 and seats against the central boss 80 on the center of the hub 75.

There is a fluid inlet pipe 140 through which hydraulic fluid is introduced to drive the piston 138 to the left as viewed in FIGURE 3. Appropriate valve connections between the pipe 117 and the pipe 140 cause one to be ex hausting as the other is introducing hydraulic fluid, and vice versa. Thus, when hydraulic fluid is being introduced through the pipe 117 to the space between the faces 79 and 108, hydraulic fluid is being exhausted through the pipe 140, and the crosshead 90 is driven to the left from the position shown in FIGURE 3 to the extreme left position in which the lugs 84 and 85 stop against the surfaces 100 and 101 on the lugs 96 and 97. On the other hand, for a quick opening of the space between the rollers 34 and 129, the control is reversed, and fluid is exhausted from the pipe 117 as it is introduced in the pipe 140. Since there is no load against withdrawing the roller 129, other than the inertia of the heavy mechanism, the much smaller piston and cylinder assembly can be used to draw the crosshead 90 to the position shown in FIGURE 3, at which the lugs 84 and 85 stop against the surfaces 104.

In operation, the roller assemblies 23 and 25 are properly adjusted to straighten or polish a bar or rod 145 passing between the rolls 34 and 129. These adjustments include adjusting the angle of the axis of the roll 34 by operation of the nut 26 and adjustment of the angle of the axis 129 by operation of the shaft 27. These adjustments are known in the art.

By linkage connections not shown, the adjustment of the axis of the roller 129 includes rotation of the entire roller assembly 25, including the plate 124 carrying the bearings 126 and 127 and the roller 129, and the crosshead 90, the hub 75, the plate 72, and the frame section 68. Hence, when this axis of the roller 129 is changed, the frame section 68 rotates relative to the ring gear 54 and the main frame of the machine. Ordinarily, once these angles are determined, often done at the factory, they are not changed.

Thereafter, the principal operation of the machine is in movement of the crosshead 90 and the roller 129 toward and away from the concave roller 34. In this machine, the force holding the crosshead in the operating position as produced by the large hydraulic pressure area between the faces 79 and 108, is not only great enough to hold the straight roller against a bar or rod 145, but that pressure, in holding the lugs 84 and 85 tightly against the lugs 96 and 97, prevents unwanted rotation of the roller assembly 25 to change the angle of the axis of the roller 129.

Normal adjustments are made by rotating the hand wheel 64. This rotates the worm 58 which in turn rotates the ring gear 54 very slowly. This slow rotation permits extremely accurate adjustment of the spacing between the concave roll 34 and the straight roll 129 because the straight roll 129 moves when the frame section 68 moves axially responsive to rotations of the ring gear 54. The connection between the frame section 68 and the crosshead 90 is through the plate 72, the hub extensions 114 and 115, the hub 75, and the lugs 84 and 85 to either the bearing surfaces 100 and 101 or the bearing surfaces 104, depending upon the condition of hydraulic control.

The hydraulic actuated movement of the crosshead 90 and straight roller assembly 25 is as already explained. Thus, this machine provides accurate setting of the relative positions of the rollers, provides for quick opening thereof efficiently with a relatively small hydraulic cylinder, and provides the great force required to move and hold the crosshead so that the straight roller bears against the work without rotation of its axis.

This machine may be of different sizes, but the principtes of it are particularly advantageous in larger straightening machines, such as those having an inside diameter for the crosshead wall 106 of about eighteen inches.

Various changes and modifications may be made within the purview of this invention as will be readily apparent to those skilled in the art. Such changes and modifications are within the scope and teaching of this invention as defined by the claims appended hereto.

What is claimed is:

1. A straightening machine comprising a frame, a first roller supported by the frame, a crosshead supported by the frame, a second roller supported by the crosshead in opposing relationship to the frame, the crosshead comprising a cylindrical member slidable within a recess in the frame, the cylindrical member having a recess in it, the frame having a large hub of size and shape complementary to the recess and extending into the recess, whereby the crosshead can slide axially within the frame recess and about the large hub, means defining opposing walls on the crosshead recess and the large hub, means to introduce hydraulic fluid into the space between the opposing walls to urge the walls apart and cause the crosshead to slide relative to the frame in a direction to move the second roller toward the first roller, and lug and face means between the crosshead and the frame to act as stops to limit the movement of the crosshead.

2. The straightening machine of claim 1 including a small hydraulic piston and cylinder assembly between the crosshead and frame, and means to introduce hydraulic fluid into the small hydraulic piston and cylinder to ,move the crosshead relative to the frame in a direction to move the second roller away from the first roller.

3. The straightening machine of claim 1 wherein the crosshead supports a plate, the second roller being journaled in two spaced bearings, the bearings being mounted on the plate.

4. The straightening machine of claim 1 wherein the frame recess is in a section of the frame movable relative to the main part of the frame, the hub also being on the frame section, and a worm and gear train for moving the frame section relative to the main part of the frame to adjust the position of the crosshead independently of the aforesaid hydraulic fluid produced movement.

5. The straightening machine of claim 4 wherein the said frame section has a cylindrical outer Wall, and the worm and gear train comprises circumferential threads in the cylindrical outer Wall of the frame section, a ring gear having integral threads in mesh with the circumferential threads and having external threads generally parallel to the axes of the ring gear, and a worm supported by the said main part of the frame in mesh with the external threads of the ring gear, the ring gear being received within a recess in the said main part of the frame permitting the ring gear to rotate about its axis while preventing it from sliding longitudinally of its axis.

6. The straightening machine of claim 1 wherein the lug and face means comprises a bayonet joint to enable assembly of the crosshead relative to the frame.

References Cited UNITED STATES PATENTS 274,856 3/1883 Uren 72-245 336,899 3/1886 Davis 72-160 2,438,240 3/1948 Trudeau 72-160 X 3,003,374 10/ 1961 Smith 72-245 MILTON S. MEHR, Primary Examiner. 

1. A STRAIGHTENING MACHINE COMPRISING A FRAME, A FIRST ROLLER SUPPORTED BY THE FRAME, A CROSSHEAD SUPPORTED BY THE FRAME, A SECOND ROLLER SUPPORTED BY THE CROSSHEAD IN OPPOSING RELATIONSHIP TO THE FRAME, THE CROSSHEAD COMPRISING A CYLINDRICAL MEMBER SLIDABLE WITHIN A RECESS IN THE FRAME, THE CYLINDRICAL MEMBER HAVING A RECESS IN IT, THE FRAME HAVING A LARGE HUB OF SIZE AND SHAPE COMPLEMENTARY TO THE RECESS AND EXTENDING INTO THE RECESS, WHEREBY THE CROSSHEAD CAN SLIDE AXIALLY WITHIN THE FRAME RECESS AND ABOUT THE LARGE HUB, MEANS DEFINING OPPOSING WALLS ON THE CROSSHEAD RECESS AND THE LARGE HUB, MEANS TO INTRODUCE HYDRAULIC FLUID INTO THE SPACE BETWEEN THE OPPOSING WALLS TO URGE THE WALLS APART AND CAUSE THE CROSSHEAD TO SLIDE RELATIVE TO THE FRAME IN A DIRECTION TO MOVE THE SECOND ROLLER TOWARD THE FIRST ROLLER, AND LUG AND FACE MEANS BETWEEN THE CROSSHEAD AND THE FRAME TO ACT AS STOPS TO LIMIT THE MOVEMENT OF THE CROSSHEAD. 